The present invention relates to a system and device allowing accurate alignment of firearm aiming apparatus by alignment with a laser beam emitted from a housing attached to the end of the firearm's barrel. This device and the housing attachments allow the system to be adapted to various types and calibers of firearms with very little difficulty and adaption. The prior art includes various bore sighting devices combining the use of a stream of light with adjustment of the firearm aiming apparatus. However, none of the prior art discloses a system employing the attachment of a collimated beam light emitting source in exact cocentric alignment with the firearm's muzzle on the discharging end of the muzzle. Also, this device has the advantage of not requiring any special target apparatus but allows for the system to be employed by pointing the collimated beam of light with the firearm at any convenient object for adjustment of the sighting apparatus.
The use of a mandrel which aligns a housing holding the light source allows for easy adaption to various calibers of firearms. By precise sizing and allowing axial adjustability of the mandrel-housing connection the collimated beam of light can be precisely aligned with the bore of the firearm barrel.